Load balancing 2 WANs (Sat and DSL) based on protocol and interface speed

[Grub3]

Dear all,

I am writing a howto for the Tooway community, internet broadband access by satellite.

This is a tutorial for pfSense end-users willing to a firewall with Two WANs:
WAN1 is satellite and WAN2 is DSL.

In my case:

• Satellite: down 8Mb/s, up 1,5 Mb/s, ping 800 ms
• DSL: down 1Mb/s, up 128Kb/s, ping 30 ms

Satellite can go down easily, especially in case of heavy rain.

Normally, we should say satellite is the first connection and DSL is the backup,
but this is not exactly the case, for these reasons:

Satellite usage (at least Tooway) has a 50:1 ratio usage.
The bandwidth is shared by 50 users with priority to lowers users.
i.e. if you use satellite more than 50:1 ratio your bandwidth degrades.

We don't know exactly the rules degrading Sat bandwidth.
It could be usage over a 15 minutes period as well as download/upload volume.

So I would like to prioritise traffic based on:

• protocol
  Use DSL for basic needs (ntp, dns) and use load balancing for the rest.

• speed
  The ideal solution would be to load balance with a priority to DSL when traffic is low (i.e. downloading requires less than 1Mb/s) and use satellite for the rest.

After reading the docs about "trains", I understand this is not perfectly possible.
So is there a "smart" feature in pfsense to load balance from one connection to another based on WAN maximum speed.

For example say :
"WAN1" has a max downloading speed of 1Mb/s,
"WAN1" has a max downloading speed of 10Mb/s,
Use WAN2 whenever dowloading speed is more than 0,5 M/s?

[Grub3]

I had a first try and pfSense reports a warning on satellite latency, which is normal.